Lotus thinks it is ahead of Red Bull

Lotus thinks it could be the fastest Renault team at the start of the season, despite skipping the first test in Jerez.

All Renault-powered teams have struggled for mileage during testing so far and the engine manufacturer admitted that it was only now where it had wanted to be midway through Jerez. World champions Red Bull have clearly struggled so far, and despite it being Lotus' debut test this week it's lap count by day four was only five shy of Red Bull.

Lotus technical director Nick Chester is optimistic his team will improve dramatically at the next test and could head to the Australian Grand Prix in good shape.

"I think we could be the lead Renault team," he said. "We certainly haven't gone badly this week in comparison to the other Renault teams, and I know they are having a few problems. All we can do is focus on ourselves and do the best job we can. Even if we are the best Renault team, we have to push on and catch the other guys."

However, Mercedes is both faster and a lot more reliable than the Lotus at the moment, and Chester admitted it would be tough to make up enough ground in the final four days of testing to compete for wins early in the season.

"I think it is going to be tough by Melbourne, for sure. They've had effectively a couple of very good tests and got themselves to a good level. We've got a lot of progression and I don't imagine they are going to make as much improvement before Melbourne whereas we've got a lot to make. It is quite a big gap to be honest."

Cooling has been an issue for all teams, but Renault-powered cars appear to be struggling most. Chester said his engineers had gone conservative with its design in the knowledge it would be tough.

"It's really tough on these cars. The cooling requirements are so much higher than we've seen on the V8s and the systems are much more complicated, so getting a good balance is quite tough. You've not just got to get the fluid cooling right, but you've got to have a good amount of air cooling to make sure nothing under the engine cover is getting too hot. It's quite tough and we've put a lot of effort into the detail all around the power unit to try and look after the components.

"It was part of the concept of the car to give ourselves a little bit of room on that, partly because we knew there was not going to be so much time to get ready for the first race. A major cooling change is quite tricky for the first race. It's better to have a bigger margin."